Upfront: I DMed a lot from 1990 to 2005, but not D&D. So I'm decent quality and experienced, but rusty and a total novice with the 5e rules. I do believe that fun trumps rules, and that alignment describes actions rather than defines them. I also hold that Evil can be extremely selfish, not always vicious & cruel.

Lost Mine of Phandelver: Redbrand Hideout. The PCs find Bugbears playing kickball with Droop, the pathetic runt Goblin, who screeches, soils himself and passes out when the party busts in to kill.

The Bard is a pro (15-year) RPer and is written as naive & optimistic. He defends the unconscious Goblin as a victim. I made Droop exceedingly weak and pathetic (by Goblin standards) thinking that they'd send him into the wild to die. Nope, healed him up and bought him a human child's church clothes, with the intent of converting his alignment.

I found some precedent (besides Drizzt), there's some Orc hero that rejected his heritage, the DMG (p.287) refers to "However, some aasimar fall into evil,
rejecting their heritage." To top it off, I realized this morning that the Bard had put in his back story that his Circus was run by a civilized Goblin (can't believe I missed that).

So I'm planning on pushing some epic role-playing to have the Bard work with his former Ringleader to bring Droop over to the light; well, the dimness - Neutral for starters.

Is there a RAW or RAI that prohibits this?

Anyone who also throws in some ideas on how to pull this off with minimum cheese will roll their next Natural 20 because of the Karma from their generosity. So, you know, there's that.

4 Answers
4

To the contrary: it is easily supported by RAW. From the Monster Manual:

The alignment specified in a monster’s stat block is the default. Feel free to depart from it and change a monster’s alignment to suit the needs of your campaign. If you want a good-aligned green dragon or an evil storm giant, there’s nothing stopping you.

For many thinking creatures, alignment is a moral choice. Humans, dwarves, elves, and other humanoid races can choose whether to follow the paths of good or evil, law or chaos. According to myth, the good-aligned gods who created these races gave them free will to choose their moral paths, knowing that good without free will is slavery.

The evil deities who created other races, though, made those races to serve them. Those races have strong inborn tendencies that match the nature of their gods. Most orcs share the violent, savage nature of the orc gods, and are thus inclined toward evil. Even if an orc chooses a good alignment, it struggles against its innate tendencies for its entire life. (Even half-orcs feel the lingering pull of the orc god’s influence.)

This clearly puts this in the realm of campaign- or setting-specific, giving tables a lot of room to have moral complexity or just go for hey it's goblins no need to overthink this.

In Forgotten Realms, where Lost Mine of Phandelver is set by default, there are lots of examples of creatures of these "monstrous" races who are individually against the typical.

\$\begingroup\$I'd like to thank everyone for their advice, it really helped. My son's Tiefling Arcane Trickster (1st character ever & the reason I took TTRP up again) already had a CE-CN-CG arc in his background and ended up bonding with Droop on the 'evil creature becoming better' story. He is now role-playing as the fallible mentor to a Goblin Fighter NE-N convert. (I am so proud, this is the nerd dad version of 'my kid made varsity')\$\endgroup\$
– Gramor FaleMar 13 at 17:58

You're the DM; that's all up to you

There is a reason that for all creatures their alignment says that they "tend to be...". This is because a creature's experiences in life decide their alignment, not their race. Their race simply tends to influence this. Because of this, it's all up to the DM as to whether any given creature can push back against their inherent alignments and become a different alignment or have a change of ideals.

For example, a Tabaxi, a race who are usually chaotic, might have accidentally killed her friends because they were were too reckless, and as such they have become neutral instead. Or a Dwarf, a race usually built on order, saw the corruption in his society and turned to anarchy, becoming chaotic. Or for example, a certain goblin was abused most of their life, but after a group of kind-hearted adventurers showed it compassion, it realized that there were better people in the world and vowed to be one of them.

It should be hard to get a thinking creature to change their alignment. However, a goblin, especially in a situation where they were at the bottom of the heap, is likely to follow the most powerful creature that will accept it as a follower, and is going to modify its behavior to suck up to that creature. As a DM, I'd either say that it won't change its deep nature, but will follow the rules as long there's people around to keep it in line, or that it will actually adopt the new morality it finds around it, given firm encouragement. It's going to take time and hard work, as well as a group, I think; if the rest of the PC harass the goblin, the goblin is not going to see the value of "good", or more realistically, these human values.

\$\begingroup\$It could be interesting if the players just manage to put the goblin in a position to be a jerk to others. I guess reading up on human bullying victims and what issues they have in later life could be a gold mine for RPing the goblin\$\endgroup\$
– JollyJokerJan 20 at 9:56

If you have access to the new Eberron: Rising from the Last War book, they have a great take on the goblinoid races and make them playable as PCs. This means that the good old "goblin = evil and must be killed" trope doesn't need to be valid. You can take a pitiful goblin NPC and give it a valid reason for living.

So in the Eberron world, to answer your questions "Is there a RAW or RAI that prohibits this?", the answer is that goblinoids aren't inherently evil, so there's no need for Bard to convert Droop. Droop is just a victim of circumstance.

I've actually been thinking of running Lost Mine of Phandelver as a starting adventure for some new players, but setting it in Eberron.